Flexner, Simon (1863–1946)

US microbiologist and medical administrator. An academic, he isolated a strain of the dysentery bacillus in the Philippines and investigated the bubonic plague in San Francisco. He joined the Rockefeller Institute for Medical Research and served as its director (1924–35).

He was born in Louisville, Kentucky. After researching and teaching as a pathologist at Johns Hopkins, he went to the University of Pennsylvania. He was the editor of the Journal of Experimental Medicine, and, during World War I, he was commissioned in the Army Medical Corps and charged with inspecting its medical laboratories in Europe. He made several other important contributions to his field, including developing a serum for cerebrospinal meningitis and laying the groundwork for the development of polio vaccines. He wrote The Evolution and Organization of the University Clinic (1939).